Perfect replacement for the previous mailbox flag.This kit is an exact replacement for the mailbox flag used on sheet-metal Gibraltar mailboxes. It provides two ways to attach the flag, depending on the diameter of the existing hole for the flag pivot. (I've uploaded a scan of the instructions on the back of the package.)If your mailbox has a 21/64" center hole (slightly over 5/16" diameter), you use the plastic pin and circular retainer clip provided in the kit. The retainer clip may be a tight fit to snap over the end of the pin, but can be carefully "helped" into place with a careful squeeze using a pair of pliers.If your mailbox has a 13/64" center hole (slightly over 3/16" diameter), you use a plastic adapter collar provided in the kit, along with a screw and nut that you will need to buy from your hardware store. Take the adapter collar with you to the store, so that you can get a screw that fits the collar and will be long enough for you to attach the nut inside the mailbox. For a standard sheet-mailbox, the instructions say that a #8 x 3/4" machine screw and nut should fit.I was able to attach this to my mailbox in about 1 minute. So easy. It's slightly awkward to move the flag into position because the holes on my mailbox don't match up to the flag exactly, but so far it's working well.This flag was perfect and was so very easy to install. At first I wasn't sure but when I got to the mailbox it only took around 4 minutes to remove the broken one and put the new one on. Great price...It isn't as sturdy as I thought it would be, but serves the purpose.I got this because it looked like it had tabs similar to my mailbox, which is a different brand and doesn't seem to sell replacement flags any more. I did have to drill to make new holes, which was easy, but I couldn't use the template on the back of the packaging because it ripped when I had to get all the pieces out of the packaging (could be designed better - or use a utility knife to cut around the edges first) I also had to use a screw and a nut, which holds it in place. The flag didn't stand up at first because I couldn't get the nut tight enough for the tension, so had to try a few different sizes until I could get it tight enough. It does the job, but I wish it came with a screw and nut.Perfect easy to install. Works greatCheap flimsyGreat product. Really happy with itThis replaced our broken American Letter box flag perfectly.!!We didn't have a Gibraltar mailbox but we were able to get it on our mailbox. We haven't had a flag for years so it makes me happy to be able to "communicate" with the mail lady again!Was very easy to install and works great so far. Installed it a couple of months ago and so far it stays up and is easy to move up and down. Very nice red color too.Works great. I had to drill some holes into my mailbox to install it but the template on the packaging made it an easy job. Installation was quick and the flag looks and works great!